Demographic aspects of lactation and postpartum amenorrhea

Interrelations between lactation and post-partum amenorrhea are studied from the reports of about 5,000 married women included in a 1966 Follow-up Survey of Acceptors of an Intrauterine Device (IUD) in Taiwan. The length of post-partum amenorrhea and of breastfeeding are positively associated. On an average, breastfeeding delayed the resumption of menstruation by about 7 months. The association between lactation and amenorrhea is not accounted for by differences in mother’s age, parity, education and her place of residence. A multiple regression analysis suggests that (1) age affects amenorrhea both directly and through lactation, (2) parity has no independent effect on either lactation or amenorrhea, and (3) education and place of residence affect amenorrhea mainly through the cultural variations in the practice of breastfeeding.     

Gender Differences in the Association Between Stress Trajectories and Depressive Symptoms Among Middle Aged and Older Adults in Taiwan

Purpose: This study investigated the effects of gender differences on the association of chronic stress and depressive symptoms in middle-aged and older adults in Taiwan. Methods: The population base was of adults aged 50 and older in Taiwan. This study included 2,889 participants and examined the gender differences on the impacts of life stress that exhibited depressive symptoms. Results: Females were more susceptible to depressive symptoms when they felt constant stress from finances, increasing stress from jobs, and fluctuating stress from family relationships. Discussion: Gender differences were evident when assuming social roles, as were psychological susceptibilities.     

心理模拟:一种有效预防冲动购买行为的方法

冲动购买是比较典型的消费者非理性购买行为。以往关于冲动购买的文献大量集中于探讨影响消费者冲动性的因素上面,而对于消费者自我控制的研究较少。本文基于自我控制的欲望—意志力模型,运用实验方法,探讨心理模拟技术对消费者冲动购买的影响。实验结果发现,过程模拟可以显著降低消费者的冲动购买水平,而结果模拟则明显提高消费者的冲动购买水平,高低冲动特质的人在这种效果上呈现明显差异;在不加控制的情况下,高冲动特质的人更偏好结果模拟,低冲动特质的人更偏好过程模拟。     

Reducing Requirement Incorrectness and Coping with Its Negative Impact in Information System Development Projects

The negative impact of incorrect requirements on information system development (ISD) project performance has long been acknowledged. This study addresses the problem of incorrect requirements by proposing a model that combines the error reduction and coping concepts proposed by Field, Ritzman, Safizadeh, and Downing (2006) with the view that ISD is a knowledge‐intensive process. The model hypothesizes that when developers and users possess an understanding of each other's primary domain of knowledge, the prevention of incorrect requirements and the mitigation of the negative consequences of incorrect requirements tend to improve project performance. Data collected from 250 ISD professionals on the basis of their experiences of recently completed ISD projects confirmed all of our hypotheses. The results demonstrate that the eliciting of incorrect requirements can be reduced when users and developers possess cross‐domain understanding and when requirement analysis methodologies and techniques are available. Furthermore, the negative impact of incorrect requirements on project performance can be mitigated when developers have sufficient ISD knowledge and behavioral knowledge.     

能源强度的指数分解分析研究综述

指数分解分析是一个研究能源强度变化及其作用机理的良好分析框架,围绕这一方法,综述了指数分解分析在方法论方面的研究现状及其在能源领域,尤其在能源强度方面的应用研究。将我国学者关于能源强度变化的研究结论划分为3类:技术进步决定论、阶段贡献变化论和分解层次影响论,并指出了指数分解分析在研究能源强度变化机理中的三大缺陷。最后,对未来的研究方向进行了展望。     

On some optimal selection procedures for weibull populations

Consider k (k >(>)2) Weibull populations. We shall derive a method of constructing optimal selection procedures to select a subset of the k populations containing the best population which control the size of the selected subset and which maximises the minimum probability of making a correct selection. Procedures and results are derived for the case when sample sizes are unequal. Some tables and figures are given at the end of this paper.     

On the performance of some subset selection procedures

In this paper, we restrict attention to the problem of subset selection of normal populations. The approaches and results of some previous comparison studies of subset selection procedures are discussed briefly. And then the result of a new Monte Carlo study comparing the performance of two classical procedures and the Bayes procedure is presented.     

Likelihood Ratio Tests for the Non Equivalence of Means

We derive likelihood ratio (LR) tests for the null hypothesis of equivalence that the normal means fall into a practical indifference zone. The LR test can easily be constructed and applied to k ≥ 2 treatments. Simulation results indicate that the LR test might be slightly anticonservative statistically, but when the sample sizes are large, it always produces the nominal level for mean configurations under the null hypothesis. More powerful than the studentized range test, the LR test is a straightforward application that requires only current existing statistical tables, with no complicated computations.     

EOQ model for imperfective items under a one-time-only discount

In practice, when a supplier is confronted with extreme completion in markets, unanticipated surplus in inventory, or change in the production run of a product, he/she may offer a special price discount to motivate buyers to order a special quantity. The purpose of the present paper is to investigate an inventory model for imperfective items under a one-time-only discount, where the defectives can be screened out by a 100% screening process and then can be sold in a single batch by the end of the 100% screening process. The optimal order policies associated with three kinds of effective times of the reduced price are obtained. Finally, a numerical example is provided to illustrate the proposed model.